The present invention relates to underwater recovery systems, and specifically to an underwater recovery system using submarine torpedo tubes.
Unmanned underwater vehicles (UUVs) are used in research and military applications. The anticipated missions for these vehicles are quite diverse; however, some of the missions require the capability to retrieve a UUV by a submarine or other underwater recovery vehicle. This is often the case when the recovery of the UUV must be covert. Retrieval of a UUV is typically desired for several reasons including, the UUV may have a cost of several million dollars, the need to retrieve the intelligence data gathered by the UUV, and the need to prepare the vehicle for a subsequent mission.
Many options have been considered for submarine retrieval of UUVs. One option includes attaching it to the outside of the pressure hull of the submarine. However, this requires the development of an external retrieval system and increases the acoustic noise emitted by the submarine. Furthermore, a UUV attached externally to the hull of the submarine is inaccessible for data gathering and maintenance. Scuttling the UUV after it has accomplished its mission is expensive and does not allow retrieval of UUV data gathered during the mission.
Using a surface ship to retrieve the UUV destroys the clandestine nature of the mission. Further, this requires that a submarine carry multiple UUVs for multiple missions. Use of a line and hook system launched from a torpedo tube to connect with a line and hook system deployed from a returning UUV has also been considered, but this method does not align the returning UUV with the torpedo tube and launchway resulting in possible damage to the UUV or hang up when the UUV is retracted into the ship.
Without extensive modification of a submarine, the torpedo tube hatch is the preferred submarine hull opening with a large enough aperture to allow entry of the UUV upon retrieval. Torpedo tube retrieval is complicated by several factors. Typical UUV designs are weight critical and therefore, are designed with delicate control surfaces, and minimal impact and load carrying capability beyond the loads imposed by hydrodynamic forces. Even under moderate ship speed, a complex flow field exists in the torpedo tube shutter area, which exerts significant lateral forces on any vehicle attempting to exit or enter the torpedo launch system""s shutterway. Typically, space within a torpedo room is limited, thus suggesting that a torpedo tube recovery system retrieve the UWV into the torpedo tube tail first because of the possibility of insufficient space to turn the UUV around for a subsequent launch. Further, significant submarine modifications using a new hull penetration apparatus or replacing a major ship component are cost prohibitive. Single torpedo tube retrieval systems have been considered. However, single torpedo tube systems do not allow UUV designs to take maximum advantage of the full size of the torpedo tube, because some space must be left to accommodate a retrieval system in the torpedo tube. Thus a need exists for an underwater recovery system which overcomes the above obstacles and disadvantages.
A system and method for recovering a submerged device with an underwater recovery vehicle utilize the underwater recovery vehicle""s recovery tubes. A recovery member is disposed within a first recovery tube. A second recovery tube receives the submerged device. To recover the submerged device, the recovery member is extended from the first recovery tube. The recovery member has a proximate end and a distal end, and the proximate end of the recovery member remains within the first recovery tube. A capture arm is extended from the distal end of the recovery member. The capture arm is engaged with the submerged device. The submerged device is aligned with the second recovery tube. The recovery member is retracted to recover the submerged device into the second recovery tube.